Recent Applications of Three Dimensional Printing in Cardiovascular Medicine

Abstract

Three dimensional (3D) printing, which consists in the conversion of digital images into a 3D physical model, is a promising and versatile field that, over the last decade, has experienced a rapid development in medicine. Cardiovascular medicine, in particular, is one of the fastest growing area for medical 3D printing. In this review, we firstly describe the major steps and the most common technologies used in the 3D printing process, then we present current applications of 3D printing with relevance to the cardiovascular field. The technology is more frequently used for the creation of anatomical 3D models useful for teaching, training, and procedural planning of complex surgical cases, as well as for facilitating communication with patients and their families. However, the most attractive and novel application of 3D printing in the last years is bioprinting, which holds the great potential to solve the ever-increasing crisis of organ shortage. In this review, we then present some of the 3D bioprinting strategies used for fabricating fully functional cardiovascular tissues, including myocardium, heart tissue patches, and heart valves. The implications of 3D bioprinting in drug discovery, development, and delivery systems are also briefly discussed, in terms of in vitro cardiovascular drug toxicity. Finally, we describe some applications of 3D printing in the development and testing of cardiovascular medical devices, and the current regulatory frameworks that apply to manufacturing and commercialization of 3D printed products.Cells 2020, 9, 742 2 of 33 Cells 2020, 9, 742 3 of 33 in digital modeling softwares without the need for file type conversion [16]. Several medical image segmentation softwares are available; some of these are open-source and freely accessible, while others are commercial, licensed products. From the DICOM dataset, the target anatomic geometry is identified and segmented based on properties such as contrast or brightness [17]. As a result, segmentation masks are created such that pixels with the same intensity range are grouped and converted into 3D digital models using rendering techniques. These segmented digital models are then exported out in the standard tessellation language (STL) file type, which is the industry standard for 3D objects and 3D printing software [17]. Nevertheless, STL files do not contain color information and in order to print in multiple colors, a different file format will need to be used. For example, virtual reality modeling language (VRML) and additive manufacturing file format (AMF) provide multiple color and material options [18]. Once segmentation is completed, the final 3D digital model may be further modified within computer-aided design (CAD) software. The main post-processing adjustments of the 3D model are: Repairing errors and discontinuities that sometimes arise in the image segmentation and exporting processes, smoothing of the surface of the model due to scaling errors resulting from the resolution of the original medical image, and addition of other...

Aortic Valve Stenosis and Mitochondrial Dysfunctions: Clinical and Molecular Perspectives

“…To better study the physiological status of calcified aortic valves, several 3D bioprinted CAVS models have been taken advantage of (well discussed in [ 56 ]). A 3D model with encapsulated HAVICs able to reproduce leaflet-layer biomechanics was created for the first time recently, and it helps in the study of AS in an environment more similar to reality [ 57 ].…”

Advances in 3D bioprinting technology for cardiac tissue engineering and regeneration

“…There have been reports on the use of innovative bioinks and strategies such as using the emerging extrusion-based floating 3D printing to engineer eye-catching vascularized contractile myocardial parts or heart-shape constructions, which collectively marks an impressive milestone in the industry [ 162 , 163 ]. However, these artificial prints, compared to the hearts of large mammals or primates, are still naive in their generation of both the input and output mechanical strengths for long-term effects.…”

Cardiac Regeneration: the Heart of the Issue

“…The myocardium is a complex tissue in which cardiomyocytes are interlaced with nonmyocyte cells to generate an intricately organized 3D structure with an elaborate vasculature system and specific physiological, biomechanical, and electrical properties. Currently, the most advanced technique for fabricating myocardial implants endowed with complex biomimetic features recapitulating the tissue native physiochemical and biomechanical characteristics is 3D bioprinting [56]. This is a rapid prototyping and additive manufacturing technique that enables the fabrication with high precision through a layer-bylayer building process of tissue-like constructs replicating the complex architecture of biological systems [57].…”